It is known to limit the fuel metered to an internal combustion engine by determining, with the aid of a characteristic, the maximum amount of fuel that may be injected into the internal combustion engine at a specific rotational speed. This full-load characteristic is generated by specific limit values of the internal combustion engine. Thus, for example, only such an amount of fuel may be injected that the exhaust gas temperature of the internal combustion engine does not exceed a specific value. The same applies to the rotational speed of the internal combustion engine. More specifically, only such an amount of fuel may be injected that the rotational speed of the internal combustion engine does not exceed a specific value and that the internal combustion engine is not damaged thereby. Further, such limits may be established, for example, by setting limit values for the pollutant emission of the exhaust gases of the internal combustion engine and by setting limit values for the maximum permissible pressure in the combustion chamber of the internal combustion engine, et cetera.
In the development of an internal combustion engine, this full-load characteristic is determined on the basis of tests, for example. In subsequent series production of the internal combustion engine, the maximum amount of fuel to be injected is set for each rotational speed on each individual engine in accordance with the determined characteristic.
This method for full-load limitation of an internal combustion engine has the disadvantage that the amount of air supplied to the internal combustion engine is not taken into account in the determination of the full-load characteristic. As a result, changing air pressure or changing air temperature greatly change, for example, the composition of the exhaust gases of the internal combustion engine or also its power rating. Further, the fixed allocation of a maximum amount of fuel to be injected at a specific speed does not make allowance for the manufacturing tolerances that occur in the production of the individual internal combustion engines. Accordingly, the individual engines will have different torque patterns.